... menufacturer with 20 years reputation. Features: 1. Nonwoven filter paper for air filters has high strength, low shrink ratio, heat ... resistance, good stability and air permeability. 2. It is waterproof, light-stopped, acid/alkali ... noncorrosive gases, such as compressed air , oxygen,nitrogen, fuel gas etc, and can be used in serveral kinds of vehichle filter element.